Laminitis in horses 101: Key information for all horse owners

Laminitis in horses is a serious and potentially life-threatening condition that affects the hooves. Essentially, it is inflammation of the laminae, the tissue that connects the hoof wall to the pedal bone inside the hoof. The inflammation is caused by lack of nutrients (circulation) to the lamellae structure. There are a few common causes of laminitis, and early warning signs that, when you know what to look for, enable you to take action before things get really bad. In this article we show you how to recognise laminitis, and what you can do to prevent it.

Causes of laminitis in horses

Laminitis can result from a variety of factors, often linked to the horse's diet, lifestyle, and overall health. Let's start by talking about the most common cause of laminitis: the diet.

The diet

The most common cause of laminitis is the horse's diet. Excessive sugars and starches, either in the horse's hard feed or pasture (or both!), can lead to inflammation in the laminae. This can happen fairly quickly too - some horses only need an hour or two on lush spring grass, and soon after you can feel a digital pulse in their feet.

Keep in mind that horses, whilst grazing animals, are not designed to graze on the kind of high-sugar, lush grass that most modern pastures are full of. In the wild they would travel great distances, looking for and nibbling on tough , dry grasses, various plants, roots and lots more, whilst moving between food and water sources almost constantly. This is very different from the modern domesticated horses' living environment, and that is causing issues for many horses.

It is said that almost 100% of laminitis is caused by hormone dysregulation (Cushings/PPID, Insulin Resistance/IR). However, laminitis exists on a continuum and the horses on the lower end of the scale far outnumber the horses who "founder" catastrophically. These horses do not have PPID or IR and most of the time they are not even overweight.

It is far better to "read the hoof" rather than to rely on the horse's body score to assess risk - or presence of laminitis. (BTW, if you want to learn to "read" the hoof accurately, check out our Tier 1 Online course!)

Other causes of laminitis in horses

There are other causes of laminitis too, such as stress and trauma, which can cause supporting limb laminitis, for example. Wormers or vaccines can also cause the laminae to become inflamed, as can ingesting certain toxins, such as black walnut shavings. Cortisone injections are a common cause of laminitis. A mare may suffer a retained placenta during birthing of their foal, which can lead to laminitis. All these causes are far fewer in numbers however, than the purely diet and lifestyle induced cases.

Early warning signs of laminitis

Lameness, heat in the hoof and raised digital pulses are some of the early warning signs of laminitis in horses. All three normally only happen in the hoof that is affected, so it can be just in one hoof, or more. Most horses were not completely fine yesterday, and developed laminitis today. Therefore, you will see other signs in the hooves as well. It's just that we don't really take note of things unless the horse is obviously lame.

Usually the horse has some trouble turning on a tight radius, they may "shuffle" with a slightly shortened stride instead of move out freely, and show excessive or sudden discomfort on hard or rough surfaces. They may be reluctant to go forward under saddle, and display a variety of behaviour problems when ridden.

Another sure tell-tale sign of inflammation in the laminae (and this can happen even before any of the above mentioned things) is a "puffy" coronet band, leading to an event line as the hoof grows. When the laminae gets inflamed, the coronet band raises up. On a healthy hoof, the coronet band should be a smooth transition between the hairy leg and the hoof wall. If you slide your finger over the area and feel a distinct bump over the coronet band, that tells you that there's at least a low level of inflammation going on - this is the time to take action, not later! There is a difference between a saturated coronet band due to wet weather, and an inflamed one.

This is the best real-time assessment tool- everything else that shows in the hoof wall, has already happened in the past.

Event lines on the hoof are proof of historical inflammation in the hoof. Since the hoof grows approximately 10mm a month, you can date the inflammation by measuring how far down the highest ring is from the coronet band. If it's 20mm down, that means the laminitic episode was approximately 2 months ago.

Flared hoof walls, white line separation (seedy toe), abscesses, cracks and thin soles are also all symptoms of laminitis.

Consequences of untreated laminitis

If laminitis is not treated promptly, it can cause the horse chronic pain and irreversible changes in the internal hoof. Laminitis causes the soles to become thin, and if the heels are high, the pedal bone to rotate inside the hoof capsule. In very severe cases, the pedal bone can penetrate through the sole, which is incredibly painful for the horse and an extremely serious situation that requires careful and knowledgeable care.

Horses who haven't catastrophically foundered, yet live with chronic "lower grade" laminitis, will have damage to the edges of their pedal bones and often a reduced capacity to grow sole, among other issues that are sadly often overlooked or incorrectly diagnosed.

Top tips for treating laminitis

If you suspect your horse has laminitis, you should immediately review their diet and reduce their combined sugar and starch intake to an absolute minimum. The recommended amount is under 10%.

Do not starve the horse! Low sugar forage (hay) should be available on a free choice basis.

If you cannot access such forage, you may need to think outside the box a little bit - but starving a laminitic horse whether fat or not, is the wrong thing to do.

There are also other important additions to the diet such as appropriate minerals and salt.

If the horse is thin, there are safe feeds available - it's best not to ask the feedstore or believe what the bag says, but rather consult you barefoot hoof care professional for advice. Some independent nutritionists are a good source of information too.

Some people will tell you that the horse needs to be on box rest and immobile, but keep in mind that movement is vitally important for proper hoof function and blood circulation in the hooves - and blood circulation is crucial for healing. Therefore most barefoot hoof care professionals (including us) will recommend that you do this instead:

1. Trim the hooves anatomically correctly, to promote proper alignment and healing. All horses are best trimmed weekly but for laminitis cases, this can be a crucial, make-or-break factor.

2. Use hoof boots that offer plenty of cushioning. Add thick soft pads into the boots for added comfort.

3. Encourage movement: if the hooves are appropriately trimmed and supported, movement does not cause further damage. It increases circulation.

Conclusion

Laminitis in horses is a serious condition that requires vigilant care. The sooner you recognise the early signs of laminitis and take action, the better. Providing your horse with a low-sugar diet and correct hoof care are keys to preventing and rehabilitating laminitis.

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